At least some embodiments of the present disclosure pertain generally to the efficient use of a plurality of physical letter sorters that are physically located at a secondary mail processing facility, with the members of the plurality having a different number of letter holding pockets, for production of assembled groupings of mail items going to a single mailing address (known as STATEMENTPACKS℠ or Packs), wherein the secondary mailing facility is physically outside of or distant from a home or primary mailing facility. Typically, the primary mailing facility is a facility at which a large number of mail items are generated (e.g., computer received and created, printed, assembled into individual packaging (e.g., envelop, plastic wrapper, etc.), etc.), however, the secondary mailing facility carries out similar operations, but at the distant location with, normally, fewer pieces of processing equipment, but having the plurality of different sized (pocket number) letter sorters.